Non-diffusing magenta color couplers



United States Patent 6 Claims. (01. 96-55) The present invention relates to color couplers in which the non-diffusing group comprises a long aliphatic chain substituted by two hydroxy groups, the silver halide emulsions containing such couplers and to the production of colored photographic images in the presence of such couplers.

In the production of colored photographic images it is the practice to use photographic multi-layer materials, the silver halide layers of which contain dyestuff formers. The colored images are then produced by a coupling reaction of the developer oxidation product of an aromatic amino developer with the color coupler present in each silver halide emulsion layer.

It is known to employ color formers containing nondilfusing groups such as a long aliphatic chain, the purpose of which is to prevent dilfusing of the couplers from one layer into the other. It is likewise common practice to provide such couplers with certain acid radicals such as carboxy or sulfo radicals, the alkali-metal or ammonium salts of which are soluble in water or aqueous solutions such as photographic emulsions.

It is known to use the ethyl ester of stearoylacetic acid (ethyl octadecanoylacetate) for the preparation of diffusion-resistant magenta couplers of the pyrazolone series. The said ester is condensed with hydrazines to form 3-heptadecyl-substituted pyrazolones which substituent radical makes the molecule sufficiently resistant to diffusion. In this way, however, the solubility in aqueous alkali is impaired with many of these pyrazolone couplers, in spite of the presence of solubilizing groups such as the foregoing carboxy and sulf-o radicals. It is frequently observed that a color coupler solution in gelatin at pH 7, shows a clouding due to the color coupler crystallizing after standing for only a few hours at 40 C. When such a color coupler solution is used, there is obtained after the conventional photographic processing a deviation in the color gradation as compared with a freshly prepared color coupler solution. These phenomena occur particularly frequently with color formers of the pyrazolinobenzimidazole series which are obtained from l (2-aminophenyl)-5-pyrazolones as described in German Patent No. 1,070,030.

It is among the objects of the present invention to avoid the disadvantages described above and to provide novel non-diffusing color couplers which have improved physical and photographic properties. Other objects will be apparent from the following description.

We have found that certain magenta couplers containing a 9,10-dihydroxyheptadecyl substituent radical serve as very useful color couplers for color photographic materials. This advantageous and unexpected efiect of the dihydroxyheptadecyl radical is not restricted to only certain special color coupler structures but can be observed with various magenta couplers. The color coupler structure of the color couplers is selected only according to the requirement of the color photographic material in which the coupler containing the dihydroxyheptadecyl radical is to be used. Especially suitable are, however, color couplers of the pyrazolone or pyrazolinobenzimidazole series.

Color couplers carrying such a dihydroxyheptadecyl substituent do not show any tendency to crystallize in the photographic layer, and a solution of the color former in gelatin remains completely clear for a long time at 40 C.; a flattening of the gradation compared with a freshly prepared solution is not observed.

By introducing a dihydroxyheptadecyl radical substituent into their molecules it is possible to use many valuable color couplers for color photography that could not be used because of their unfavorable solubility properties.

Couplers of the pyrazolone and pyrazolinobenzimidazole series containing a dihydroxyheptadecyl radical can be prepared'in conventional manner by using the ethyl ester of 9,10-dihydroxystearoylacetic acid instead of ethyl stearoylacetate as starting material for the pyrazolone.

Preparation of the ethyl 9,1:0-dihydroxystearoylacetate To 30 g. of sodium metal dispersed in 220 cc. of xylene is added 1.5 liters of dried benzene. In a nitrogen atmosphere, 168 g. of ethyl acetoacetate are added dropwise at 35 C. to that mixture during 1 hour and stirred for 6 hours at 30 C. Thereafter 300 g. of oleic acid chloride (9-octadecenoyl chloride) are added dropwise during 1 hour to the sodium acetoacetic ester solution and stirring is continued for another 3 hours obtaining thereby a clear solution:

19.2 g. of sodium are dissolved in 220 cc. of methanol and added to the above solution, which is stirred for another 6 hours. Water is then added and the benzene solution is separated from the aqueous layer by means of a separating funnel. After repeated extracting with water, the benzene is distilled off in vacuo. About 270 to 280 g. of ethyl oleoylacetate (ethyl 9-octadecenoylacetate) are obtained.

200 g. of ethyl oleoylacetate thus prepared are mixed with 425 cc. of formic acid. Within 15 minutes, 60 g. of a 30-percent solution of hydrogen peroxide is added dropwise at 25 C. and stirring is continued for 6 hours at 40 C. After this time, the hydrogen peroxide is consumed and thereafter the solvent is distilled off at 40 C. in vacuo. The remaining dihydroxy ester is taken up in ethyl acetate, washed neutral with sodium bicarbonate solution and thereafter with water, dried over sodium sulphate and finally the solvent is removed in vacuo. About 200 g. of ethyl 9,10-dihydroxystearoylacetate is obtained as a light yellow oil.

C H O (molecular weight 386).-Calculated: C, 68.39%; H, 10.88%; 0, 20.72%. Found: C, 68.60%; H, 10.69%; 0, 21.29%.

EXAMPLE 1 A mixture of 19 g. of phenyl-hydrazine-4-sulphonic acid, 11 g. of sodium acetate, cc. of water, 15 cc. of glacial acetic acid, 42.5 g. of ethyl 9,10-dihydroxystearoylacetate and cc. of n-propanol is refluxed for 2 hours. Thereafter, the reaction mixture is acidified with 20% aqueous hydrochloric acid and extracted by shaking with ethyl acetate. The ethyl acetate solution is washed neutral and dried over sodium sulphate. The solvent is distilled off in vacuo and the residue extracted several times with petroleum ether. There are obtained about 30 g. of 1-(4'-sulphophenyl)-3-(9,10 dihydroxyheptadecyl)-- pyrazolone (Formula I).

C H O N S (molecular weight 510).Calculated: C, 61.17%; H, 8.23%; O, 18.82%; N, 5.49%; S, 6.27%. Found: C, 61.64%; H, 8.35%; O, 18.50%; N, 5.60%; S, 6.05%.

1.5 g. of this color coupler is suspended in 5 cc. of methanol, dissolved by addition of 5 cc. of l-normalsodium hydroxide solution and cc. of water and made up with water to 100 cc. The solution is added to 100 cc. of a silver halide emulsion, which is cast in known manner on a support.

After exposure and development with diethylamino aniline, a magenta image is obtained with an absorption maximum at 530 millimicrons.

If the above color coupler solution is adjusted to a pH- value of 7, a clear solution is obtained which can be kept for a relatively long time at 40 C.

The color component solution of the magenta coupler VI, in which the hydroxy groups are lacking, and which is used for comparison purposes, becomes cloudy with return of the pH-value to 7.

EXAMPLE 2 14 g. of 4-phenoxy-3-sulphophenyl hydrazine, 6 g. of anhydrous sodium acetate, 40 cc. of water, 7 cc. of glacial acetic acid, 22 g. of ethyl 9,10-dihydroxystearoylacetate and 40 cc. of n-propanol are refluxed for 2 hours. Thereafter, the mixture is acidified with 20% hydrochloric acid and the liquid is decanted off from the semi-solid mass. The product is triturated with ethyl acetate, suction-filtered and thereafter extracted with acetone. There are obtained about g. of 1-(4'-phenoxy-3'-sulphophenyl)- 3-(9, 10-dihydroxyheptadecyl)-5 -pyrazol0ne (Formula II).

The processing of 1.6 g. of this color coupler as described in Example 1 yields a magenta image with an absorption maximum at 532 millimicrons.

EXAMPLE 3 12 g. of 4-ethoxyphenyl hydrazine-3-sulphonic acid, 6 g. of sodium acetate, 40 cc. of water, 7 cc. of glacial acetic acid, 22 g. of ethyl 9,10-dihydroxystearoylacetate and 40 cc. of n-pr-opanol are boiled under reflux for 2 hours. The mixture is then acidified with hydrochloric acid, cooled with ice and suction-filtered. The residue is extracted with acetone and there are obtained about 15 g. of 1-(4'-ethoxy-3'-sulphophenyl)-3(9,10-dihydroxyheptadecyl)-5-pyrazolone (Formula III).

The processing of 1.5 g. of this color coupler as described in Example 1 yields a magenta image with an absorption maximum at 535 millimicrons.

EXAMPLE 4 13.5 g. of 2-hydrazinobenzthiazole-S-sulpl1onic acid, 50 cc. of water, 5 g. of anhydrous sodium acetate, 12.5 cc. of glacial acetic acid, '25 g. of ethyl 9,10-dihydroxystearoylacetate and 30 cc. of isopropanol are stirred for 3 hours at 65 C. Precipitation is carried out with concentrated hydrochloric acid and ice, the mixture is suction-filtered and the residue extracted with acetone. About 16 g. of the color coupler represented by Formula IV is obtained. The processing of 1.5 g. of this color coupler in a manner similar to that described in Example 1 supplies a magenta image with an absorption maximum at 550 millimicrons.

EXAMPLE 5 12 g. of 2-nitrophenylhydrazine-4-sulphonic acid, 6 g. of anhydrous sodium acetate, 50 cc. of water, 10 cc. of glacial acetic acid,'22 g. of ethyl 9,10-dihydroxystearoylacetate and cc. of isopropanol are stirred for minutes at 80 C., 30 cc. of 45% sodium hydroxide solution are thereafter introduced dropwise and the solution is boiled for 2 hours under reflux. After acidification with 20% hydrochloric acid, the mixture is extracted with ethyl acetate and separated from the aqueous phase in a separating funnel. The ester extract is washed neutral, dried with sodium sulphate and concentrated in vacuo. The remaining oil is dissolved in 200 cc. of methanol and about 5 cc. of concentrated sodium hydroxide solution (pH 10).

Hydrogenation is carried out for 2 hours in the presence of Raney nickel at 50 C. and 50 atm. gauge. The filtrate is adjusted with hydrochloric acid to pH 7 and concentrated in vacuo. The residue is triturated with ethyl acetate and suction filtered. There are obtained approximately 15 g. of 1-(2'-amino-4-sulphophenyl)-3-(9, 10-dihydroxyheptadecyl)-5-pyrazolone. This is dissolved in cc. of n-propanol, adjusted to an acid reaction to Congo red indicator with 3% hydrochloric acid and boiled under reflux for 10 hours. After clarification with active carbon, the solvent is distilled off in vacuo, the residue is triturated with ethyl acetate and suction-filtered. After being extracted with methanol there are obtained approximately '10 g. of magenta coupler represented by Formula V.

The processing of 1.5 g. of the substance as described in Example 1 yields a magenta image with an absorption maximum at 538 millimicrons.

EXAMPLE 6 A color photographic negative film is built up in the usual manner upon an acetyl cellulose support casting thereon a silver bromide emulsionwith a diffusion-re sistant cyan coupler (for instance, the sodium salt of 1 hydroxy 2 naphthoic acid 2 N methyl N- octadecy1-5-sulphonic acid anilide), this being followed by a silver bromide emulsion with the compound described in Example 5 as magenta component, after which a yellow filter layer is cast and on top of the latter a silver bromide emulsion layer with a yellow coupler (for instance, the sodium salt of 4-stearoylaminobenzoyl-acet- 3-5'-dicarboxyanilide). The matching of the three emulsion layers is effected in conventional manner in such a way that after exposure of a stepped wedge with white light, the color development leads to a neutral grey neg.- tive stepped wedge.

The negative film is exposed to an object to be reproduced processed in ordinary processing baths including a developer solution containing a p-diethylamino aniline developer substance to produce a multi-color negative image, and thereafter printed onto a multi-color positive material, wherein after ordinary processing a positive image of very good color quality is obtained.

Similar results are obtained if the magenta coupler of the above described color-photographic material is replaced with one of the following color couplers:

Compound of Formula VIII prepared by reaction of 4-methyl-phenyl-hydrazine with ethyl 9,10-dihydroxystearoylacetate;

Compound of Formula IX prepared by reaction of phenylhydrazine with ethyl 9,10-dihydroxystearoylacetate;

Compound of Formula XII prepared by reaction of nitro-phenyl-hydrazine with ethyl 9,10-dihydroxystearoylacetate;

Compound of Formula XIII prepared by reduction of the nitro group of color coupler XII;

Compound of Formula XIV prepared by acylation of color coupler XIII with acetic anhydride;

Compound of Formula XV prepared by condensation of 2-nitro-phenyl-hydrazine with ethyl 9,10-dihydroxy stearoylacetate followed by reduction and cyclization as described in Example 5;

Compound of Formula XVII prepared in the same manner as compound having Formula XV using 2-nitro- 4-methyl-phenyl-hydrazine as starting compound;

Compound of Formula XVIII prepared in the same manner as compound having Formula XV using as starting compound 2-nitro-S-chloro-phenyl-hydrazine;

Compound of Formula XIX prepared in the same manner as compound having Formula XV using as starting compound 2-nitro-4-methoxy-phenyl-hydrazine;

Compound of Formula XX prepared in the same manner as compound having Formula XV using as starting compound 2,4-dinitro-phenyl-hydrazine;

Compound of Formula XXI prepared by reaction of color coupler XX with acetic anhydride.

The light-sensitive emulsions containing one of the above listed color couplers are prepared as described in Example 8.

EXAMPLE 7 The color coupler of Formula XVI, which is 8-carboxy 3 dihydroxy heptadecyl 1,5 pyrazolinobenzirnidaZ-ole (1,2), .is prepared by reaction of 2-nitrophenyl-hydrozine-4-carboxylic acid with ethyl 9,10-dihydroxystearoylacetate, hydrogenation of nitrophenyl pyrazolone obtained thereby and cyclization as described in Example 1.

1.5 -g. of this color coupler are suspended in 5 cc. of methanol, dissolved by addition of 5 cc. of l-normalsodium hydroxide solution and cc. of water and made up with water to 100 cc. The solution is added to 100 cc. of a silver halide emulsion, which is cast in known manner on a support.

After exposure and development with diethylamino aniline, a magenta image is obtained with an absorption maximum at 535 millimicrons.

If the above color coupler solution is adjusted to a pH value of 7, a clear solution is obtained which can be kept for a relatively long time at 40 C.

Similar results are obtained by using the color couplers of Formulae X and XI which are prepared by reaction of phenylhydrazine-4-carboxylic acid and phenyl-hydrazine- 3,5-dicarboxylic acid, respectively with ethyl 9,10-dihydroxystearolyacetate.

EXAMPLE 8 The color coupler of Formula VII is prepared by reaction of 3-chlorophenyl hydrazine with ethyl 9,10-dihydroxystearoylaoetate.

6 g. of this color couplier dissolved in 20 cc. of ethyl acetate are emulsified with 160 cc. of a 10 percent solution of gelatin containing 1 g. of lauryl sulphate by means of a colloid mill. The resulting emulsion is dried.

6 g. of this dried product are redispersed in 100 cc. of water and mixed with 100 cc. of a silver halide gelatin emulsion. The resulting final emulsion is cast onto a support of paper or a transparent film of a synthetic polymer such as cellulose esters, polyesters formed from terephthalic acid and ethylene glycol, and polycarbonates formed from bisphenols and the like.

After exposure and development with a suitable colorforming developer such as diethylamino aniline a magenta image is obtained.

Having thus described our invention, we now state that our invention is capable of numerous variations. It will be clear to those skilled in the art that the color couplers, according to our invention, can be used in any color photographic material such as mono-layer or multilayer positive or negative material or reversal color films. The non-ditfusing color couplers according to the invention can be used in combination with any sensitizers, antifog agents, stabilizers or the like which are known to be employed in color photographic material. With regard to the utility for multi-layer color films it should be pointed out that the layer arrangement or sensitizationcolor-relationship are not especially critical. Although the binding agent of the layers in which the color couplers are to be used is preferably gelatin, other layer forming hydrophilic agents can be used such as carboxy cellulose, polyvinyl alcohol or the like. The processing of the exposed color material, containing in one layer a magenta coupler according to the invention, is accomplished in a manner well known by first developing the material with a developer composition containing a color forming developer. Said developers generally spoken are characterized by a primary amino group or a substituted amino group, the su'bstituent of which is split off during the development, e.g., as described in German Patent No. 926,713. Very useful color developers are, for example, N,N diethyl p phenylene diamine, N ethyl- N hydroxy ethyl p phenylene diamine, N butyl- N sulphobutyl p phenylene diamine, N ethyl N- methyl sulfoamino-ethyl-p-phenylene-diamine or derivatives thereof being substituted in the phenylene nucleus, furthermore, 4-aminopyrazolone and derivatives thereof. The developer composition may be alkalized -by alkalimetal carbonates, tertiary alkali-metal phosphates or the like alone or in combination with small amounts of alkalimetal hydroxides.

The developers may contain any stabilizing agents, antifog agents and compounds protecting the composition against oxidation such as alkali sulphites or salts of hydroxylamine. The developing is followed by bleaching and fixing the color films. These procedures are well known to any person having ordinary skill in the art and accordingly are not described in detail.

SOaH

(VII) (VIII) SOaH (XIII) (XIV) (XVII) (XVIII) (XIX) NII-OO CH3 I OCH;

What is claimed is:

1. A process for the production of a magenta-colored photographic image which comprises developing an exposed silver halide emulsion layer containing a non-diffusing color coupler that is capable of forming a magentacolored image upon reaction with the oxidation products of a primary amine color-forming developer, which color coupler is a member of the group consisting of 5-pyrazolone and 1,S-pyrazolinobenzimidazole(l',2') color couplers substituted in the 3 position by a 9,10-dihydroxyheptadecyl radical, and subsequently bleaching and fixing the said developed silver halide emulsion layer.

2. A light-sensitive silver halide containing photographic emulsion layer containing a color coupler of the group consisting of S-pyrazolone and 1,5-pyrazolinobenzimidazole(1',2') color couplers substituted in the 3 position by a 9,10-dihydroxyheptadecyl radical.

3. A photographic material composed of a plurality of superimposed silver halide layers each of which is sensitive to dilferent regions of the visible light spectrum, at least one layer of which contains a color coupler of the group consisting of 5-pyrazolone and 1,5-pyrazolinobenzimidazole(1,2) color couplers substituted in the 3 position by a 9,10-dihydroxyheptadecyl radical.

4. A light-sensitive silver halide containing photographic emulsion layer containing 1-(4-sulfonphenyl)-3- (9,10-dihydroxyheptadecyl)-5-pyrazolone.

5. A light-sensitive silver halide containing photographic emulsion layer containing l-(4-phenoxy-3-sulfophenyl)-3-(9,IO-dihydroxyheptadecyl)-5-pyrazolone.

6. A light-sensitive silver halide containing photographic emulsion layer containing 3-(9,l0-dihydroxyheptadecyU-1,S-pyrazolinobenzimidazole(1,2').

References Cited by the Examiner UNITED STATES PATENTS 2,213,986 9/40 Kendall et al. 9655 2,892,714 6/59 Wahl et a1. 96-55 3,061,432 10/62 Menzel et a1. 9655 NORMAN G. TORCHIN, Primary Examiner.

LOUISE P. QUAST, Examiner. 

1. A PROCESS FOR THE PRODUCTION OF A MAGENTA-COLORED PHOTOGRAPHIC IMAGE WHICH COMPRISES DEVELOPING AN EXPOSED SILVER HALIDE EMULSION LAYER CONTAINING A NON-DIFFUSING COLOR COUPLER THAT IS CAPABLE OF FORMING A MAGENTACOLORED IMAGE UPON REACTION WITH THE OXIDATION PRODUCTS OF PRIMARY AMINE COLOR-FORMING DEVELOPER, WHICH COLOR COUPLER IS A MEMBER OF THE GROUP CONSISTING OF 5-PYRAZOLONE AND 1,5-PYRAZOLINOBENZIMIDAZOLE (1'',2'') COLOR COUPLERS SUBSTITUTED IN THE 3 POSITION BY A 9,10-DIHYDROXYHEPTADECY RADICAL, AND SUBSEQUENTLY BLEACHING AND FIXING THE SAID DEVELOPED SILVER HALIDE EMULSION LAYER. 